Device and method for connecting a blood pump without trapping air bubbles

ABSTRACT

An apparatus and a method for connecting medical tubing or any other type of fluidic circuit conduits (e.g., cannulae) to a ventricular assist device (“VAD”) or any other pumping device used for blood pumping during cardiac circulatory support for vascular surgery. The apparatus and the method prevent air bubbles from entering a cardiac circulatory support system when connecting cannulae to a VAD that may later enter the blood stream of a patient during cardiac surgery, and also provide for purging any air bubbles that may have entered the cardiac circulatory support system during a cannulae-VAD connection.

RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application No. 61/040,612, entitled “Device andMethod for Connecting a Blood Pump without Trapping Air Bubbles,” whichwas filed Mar. 28, 2008, and which is incorporated by reference hereinin its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to interconnecting cannulaeused with medical devices, and more particularly, to connecting andpurging devices connected to cannulae for utilization in medicalprocedures.

2. Related Art

As heart disease has become more common in recent decades, for severalreasons, which may include nutritional and life-style choices, new andimproved medical procedures have been developed to combat this medicalcondition. Procedures for treating or preventing heart failure typicallyrequire invasive surgery. Such procedures may involve using pumpingdevices for cardiac circulatory support before, during, and after theopen heart surgery, or as a bridge in the case of a completecardiopulmonary bypass, e.g., a heart transplant. Examples of cardiaccirculatory support devices include rotary and axial blood pumps, aswell as ventricular assist devices (“VADs”), which are used tosupplement the heart's pumping action during and after surgery.

Cardiac circulatory support devices are connected to a patient's heartusing medical tubing, (i.e., cannulae) that is connected to the heart atappropriate locations according to standard surgical practices. Somecardiac circulatory support systems include a pneumatic drive unit thatconnects to an air supply. The cardiac circulatory support systems mayalso include a pump that is magnetically or electrically powered.

FIGS. 1A-1C illustrate three examples of configurations ofpatient-implanted VADs. FIG. 1A shows a schematic illustration of a VAD100 implanted in a patient as a left ventricular assist device, or LVAD.The LVAD 100 is connected to an outflow cannula 102, which is surgicallyconnected to the left ventricle of the heart 108. The LVAD 100 is alsoconnected to an inflow cannula 104, which is surgically connected to thepatient's aorta 106. The LVAD 100 receives blood from the left ventricle108 through the outflow cannula 102 and delivers the blood through theinflow cannula 104 to the aorta 106 for circulation throughout thepatient's body.

FIG. 1B shows a schematic illustration of a VAD 120 implanted in apatient as a right ventricular assist device, or RVAD. The RVAD 120 isconnected to an outflow cannula 122, which is surgically connected tothe right atrium of the heart 124. The RVAD 120 is also connected to aninflow cannula 126, which is surgically connected to the pulmonaryartery 128. The RVAD 120 receives blood from the right atrium 124through the outflow cannula 122 and delivers the blood through theinflow cannula 126 to the pulmonary artery 128.

FIG. 1C shows a schematic illustration of two VADs 140 a and 140 bimplanted in a patient as a bi-ventricular assist device, or BIVAD. Thefirst VAD 140 a is connected to an outflow cannula 142 a, which isconnected to the right atrium of the heart 124. The first RVAD 140 a isalso connected to an inflow cannula 144 a, which is connected to thepulmonary artery 128. The second VAD 140 b is connected to an outflowcannula 142 b, which is connected to the left ventricle of the heart108. The second VAD 140 b is also connected to an inflow cannula 144 b,which is connected to the aorta 106. The BIVAD 140 a, 140 b assists theright atrium and the left ventricle, respectively, of the heart 108 bycombining the operations of both an RVAD and an LVAD.

FIGS. 2A-2C illustrate three examples of configurations of anextra-corporeal VAD. FIG. 2A shows a schematic illustration of a VAD 200connected extra-corporeally to a patient as an LVAD. The LVAD 200connects to an outflow cannula 202, which is surgically connected to theleft ventricle of the heart 208. The LVAD 200 also connects to an inflowcannula 204, which is surgically connected to the aorta 206. The LVAD200 is maintained outside of the patient's body. The outflow and inflowcannulae 202, 204 enter the patient at openings 210, and extend up tothe left ventricle 208 and the aorta 206, respectively.

FIG. 2B is a schematic illustration of a VAD 220 connectedextra-corporeally to a patient as an RVAD. The RVAD 220 connects to anoutflow cannula 222, which is surgically connected to the right atrium224. The RVAD 220 is also connected to an inflow cannula 226, which issurgically connected to the pulmonary artery 228. The outflow and inflowcannulae 222, 226 enter the body at opening 230, and extend up to theright atrium 224 and the pulmonary artery 228, respectively.

FIG. 2C is a schematic illustration of two VADs 240 a, 240 b connectedextra-corporeally to a patient as a BIVAD. The first VAD 240 a isconnected to an outflow cannula 242 a, which is surgically connected tothe right atrium of the heart 224. The first VAD 240 a is alsosurgically connected to an inflow cannula 244 a, which is surgicallyconnected to the pulmonary artery 248. The second VAD 240 b is connectedto an outflow cannula 242 b, which is connected to the left ventricle ofthe heart 208. The second VAD 240 b is also connected to an inflowcannula 244 b, which is connected to the aorta 252. The BIVADs 240 a,240 b are maintained outside the patient's body and assist the rightatrium and the left ventricle, respectively, of the heart 208, 224 bycombining operation of both an RVAD and an LVAD. The cannulae 242 a, 244a, 242 b, 244 b may enter the patient's body at openings 256, 258,respectively, in the patient's chest.

At some time before, during, or after the surgery, surgeons must connecta cardiac circulatory support device, such as the VADS shown in FIGS. 1Athrough 2C, to the cannulae that are connected to the patient's heart.This connection requires a connector that is precisely adapted to thecannulae to reduce turbulence in the blood flow in the cardiaccirculatory support system, avoids fluids draining from the inside ofthe cardiac circulatory support system, and also avoids the introductionof air or other undesired gasses into the cardiac circulatory supportsystem. During the process of making the connection, the air volume inthe cannulae can be replaced by saline solution, blood, or any otheracceptable liquid. In general, saline solutions are any sterile solutionof sodium chloride in water. These saline solutions are available invarious formulations, for different purposes, such as intravenousinfusion, rinsing contact lens, and nasal irrigation.

The elimination of any air residue inside the cannulae or any part ofthe cardiac circulatory support system is necessary because theintroduction of air bubbles, i.e., air embolisms, into the patient'scirculatory system may result in serious complications. For example, airbubbles can block or occlude the blood vessels in the brain, therebycausing the loss in function of one or more parts of the body. Largervolumes of air may also result in venous air embolisms, hypotension, ordysrhythmias, or even death, when the air intake is rapid. Another riskis a pulmonary embolus occlusion, which is the blockage of an artery inthe lungs by an air embolism. The air embolism results in an increase ofdead space. Such a blockage could result in pulmonary constriction.

Large and rapid volumes of air entering into the blood stream may fillthe right auricle and produce an air restriction that could result inthe closing of the right ventricle, venous return diminution, andcardiac diminution. Myocardial ischemia and cerebral ischemia may thenset in shortly.

In some cases, even if air replacement has been adequately and carefullyperformed, air bubbles may get trapped and remain inside the cannulae.Standard attempts to remove the trapped air bubbles involve extractingthe bubbles with a syringe or by slapping the cannulae. Both methods areoften time-consuming and somewhat imprecise.

Several types of apparatus and methods have been developed for purgingunwanted fluids from a closed circulatory system. However, theseapparatuses and methods are typically excessively complex for simpleapplications, such as the purge of cannulae during a surgical procedure.

In addition, the connection itself may create problems during theconnection of the cannulae to a VAD. Different cannulae and medical tubeconnectors have been developed to address such problems. However, theyare typically excessively complex solutions for simple applications,such as connections to medical terminals. In addition, existing designsfor securing the connections and for preventing the components fromrelative movement during operation generally mitigate against providingpurging options for the connection. And certain purging methods make itmore difficult to make the connection in a vertical position to a VAD inclosed circulatory system.

Thus, there is a need for improved systems and methods for connectingcannulae to a blood pump that have the ability to purge air from theblood or other liquid inside the cannulae and elsewhere throughout thecardiac circulatory support system.

SUMMARY

A disposable purging (“DIP”) device for connecting cannulae to cardiaccirculatory support devices for use in cardiac circulatory supportsystems is disclosed. The DIP device is operable to purge air bubblesfrom the cannulae and from the cardiac circulatory support system andalso to prevent the entry of air into the cardiac circulatory supportsystem. The DIP device may include a device body having a distal endingand a proximal ending, with an inner semi-closed flexible ringpositioned towards the distal ending of the device body, and an airoutlet having an external conduit extending radially from the devicebody.

A method of using such a DIP device connect cannulae to a cardiaccirculatory support device is also disclosed. In one example method ofoperation, DIP devices in accordance with the invention are attached tothe inflow and output ports of a ventricular assist device (“VAD”) andthe VAD/DIP device assembly is filled with a liquid, such as a salinesolution. Each of the DIP devices are then alternatively occluded andfilled with additional liquid to expel any air tapped in the assembly.Once this is completed, the VAD/DIP device assembly is maneuvered toallow for the insertion of the cannulae into the assembly while fillingthe cannulae and the assembly with the liquid. After the purging of anyair in the DIP devices, the cannulae are inserted further into theassembly and connected to the VAD and the DIP devices are then removedfrom the VAD/cannulae assembly.

Other systems, methods and features of the invention will be or willbecome apparent to one with skill in the art upon examination of thefollowing figures and detailed description. It is intended that all suchadditional systems, methods, features and advantages be included withinthis description, be within the scope of the invention, and be protectedby the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingfigures. The components in the figures are not necessarily to scale,emphasis instead being placed upon illustrating the principles of theinvention. In the figures, like reference numerals designatecorresponding parts throughout the different views.

FIG. 1A shows a schematic illustration of a ventricular assist device(“VAD”) implanted in a patient as a left ventricular assist device(“LVAD”).

FIG. 1B shows a schematic illustration of a VAD implanted in a patientas a right ventricular assist device (“RVAD”).

FIG. 1C shows a schematic illustration of two VADs implanted in apatient as a biventricular assist device (“BIVAD”).

FIG. 2A shows a schematic illustration of a VAD in use extracorporeallywith a patient as an LVAD.

FIG. 2B shows a schematic illustration of a VAD connectedextracorporeally to a patient as a RVAD.

FIG. 2C shows a schematic illustration of two VADs connectedextracorporeally to a patient as a BIVAD.

FIG. 3 shows a transparent perspective view of an example of adisposable purging (“DIP”) device for connecting cannulae to a cardiaccirculatory support device according to the present invention.

FIG. 4 shows a transparent exploded perspective view of the example DIPdevice shown in FIG. 3.

FIG. 5A shows a cross-sectional view from the distal ending of theexample DIP device shown in FIG. 3.

FIG. 5B shows a cross-sectional view along line A-A in FIG. 5A.

FIGS. 6A and 6B illustrate an example of utilizing a DIP device inaccordance with the invention to connect cannulae to a cardiaccirculatory support device.

FIG. 7 shows a perspective view of an example assembly that includes anexample DIP device in accordance with the invention, two cannulae and aVAD.

FIG. 8 shows an exploded perspective view of the assembly shown in FIG.7.

FIG. 9 shows a longitudinal cross-sectional view of the assembly shownin FIG. 7.

FIG. 10 shows a perspective view of an example VAD that may be used inthe assembly shown in FIG. 8.

FIGS. 11A and 11B illustrate attachment of DIP devices in accordancewith the invention to the example VAD of FIG. 10.

FIGS. 12A and 12B illustrate adding a liquid to the VAD/DIP deviceassembly in FIG. 11B.

FIGS. 13 and 14 illustrate occluding the DIP devices and turning theVAD/DIP device assembly upside-down.

FIGS. 15A and 15B illustrate adding more liquid to the VAD/DIP deviceassembly.

FIG. 16 shows the VAD/DIP device assembly clamped and filled with liquidprior to connection of the cannulae to the VAD.

FIGS. 17A, 17B, and 17C illustrate connection of one of two cannulae, anoutflow cannula, to the VAD/DIP device assembly.

FIG. 18 illustrates the outflow cannulae inserted into the VAD/DIPdevice assembly.

FIG. 19 illustrates removal of the clamp occluding the DIP device.

FIG. 20 illustrates connection of the inflow of the VAD to the outflowcannulae inserted at the distal ending of the inflow DIP device.

FIG. 21 shows the second cannulae, i.e., the inflow cannulae, prior toinsertion into the DIP device that is still occluded.

FIGS. 22, 23, and 24 illustrate connection of the inflow cannulae to theVAD/DIP device assembly.

FIGS. 25A-25D illustrate an example of a method for removing air bubblesthat entered the assembly during the insertion of the cannulae into theDIP devices.

FIG. 26 illustrates removal of the clamp occluding the second DIP deviceduring the insertion of the inflow cannulae to the VAD.

FIG. 27 illustrates the inflow cannulae connected to the outflow of theVAD.

FIGS. 28A and 28B illustrate removal of one of the DIP devices from theconnection between the cannulae and the VAD.

FIGS. 29A and 29B illustrate removal of the second DIP device.

FIG. 30 shows an example connector that may be used to connect cannulaeto a VAD as shown in FIG. 29B.

FIG. 31 shows three (3) examples of cannulae that may be utilized inaccordance with the invention.

FIG. 32 shows a flowchart illustrating an example method of operationthat uses a DIP device in accordance with the invention to connectcannulae to a cardiac circulatory support device and then purge any airbubbles that may have entered the cannulae/cardiac circulatory supportdevice assembly using the DIP device.

DETAILED DESCRIPTION

In the following description of examples of implementations, referenceis made to the accompanying drawings that form a part hereof, and whichshow, by way of illustration, specific implementations of the inventionthat may be utilized. Other implementations may be utilized andstructural changes may be made without departing from the scope of thepresent invention.

FIG. 3 shows a transparent perspective view of an example of adisposable purging (“DIP”) device 300 for connecting cannulae to cardiaccirculatory support devices operable to purge air bubbles from thecannulae and from the cardiac circulatory support system and also toprevent the entry of air into the cardiac circulatory support system.FIG. 2 shows an exploded perspective view of the device of FIG. 3 thatillustrates how the components of the DIP device 300 are configuredrelative to each other.

The DIP device 300 includes a device body 302 having a distal ending 304and a proximal ending 306. The device body 302 may include an innersemi-closed flexible ring 308 positioned towards the distal ending 304of the device body 302, and an air outlet 310. An external conduit 322extending radially from the device body 302 between the distal ending304 and the proximal ending 306 is connected or linked to the air outlet310. A female plug 320 may be inserted into the external conduit 322,with a male plug 326 coupled to or capping the female plug 320 so as topermit control of the opening and closing of the air outlet 310 at theexternal conduit 322. The device body 302 includes a detachment section324 to permit removal of the DIP device 300 from a connected andair-bubble-free assembly of medical tubing and cardiac circulatorysupport devices. The detachment section 324 may include a flap 324A thatextends beyond the distal ending 304 to provide a portion of thedetachment section 324 on which the user may grasp the detachmentsection 324 to allow for pulling off and disconnecting the DIP device300.

The device body 302 generally conforms to the shape of the tubes makingup the closed fluidic circuit in which the device 300 is used. Theexample device body 302 shown in FIGS. 3 and 4 is a hollow, flexible,and transparent or translucent tubular body, and may be made of anatural or synthetic elastomeric or polymeric material. The device body302 is hollow inside, having openings at the distal ending 304 and theproximal ending 306. The proximal ending 306 connects to a circulatorysupport device, which may be a blood pump or a ventricular assist device(“VAD”), or any other type of pump or device used for circulatorysupport. The distal ending 304 connects to a cannula or other type ofmedical tubing utilized in medical applications. The device body 302 mayalso be configured to be occluded at any part of its body with clamps orother similar surgical instruments. Moreover, the length of the devicebody 302 may be easily modified by cutting or tearing the bodytransversely, so as to obtain a shorter or longer device body 302, asthe case may be, in order to facilitate the connection of cannulae tothe cardiac circulatory support device.

The DIP device 300 of FIG. 3 may be used to connect medical tubing, suchas cannulae, that may be surgically implanted in a patient forconnection to a cardiac circulatory support device. The DIP device 300facilitates connection of the cannulae to the cardiac circulatorysupport device. Once connected, the DIP device 300 also allows its usersto purge any air bubbles that may have formed in the liquid flowingthrough the cardiac circulatory support device during the connection.Typical cardiac circulatory support devices include an inflow port toreceive fluid such as blood, and an outflow port through which bloodflows out of the cardiac circulatory support device. The cardiaccirculatory support device may pump the blood or other liquid itreceives at the inflow port through the outflow port for circulationthrough the patient's body. One cannula may be implanted into thepatient to carry blood that will flow to the cardiac circulatory supportdevice and another cannula may be surgically implanted into the patientto carry blood from the cardiac circulatory support device at theoutflow port back to the patient. During connection of the cannulae tothe cardiac circulatory support device, one DIP device 300 receives onecannula at the distal ending 304. The proximal ending 306 is connectedto one of the ports of the cardiac circulatory support device. AnotherDIP device 300 is used to connect the other cannula to the other port ofthe cardiac circulatory support device.

The inner semi-closed flexible ring 308 is positioned in the innersurface of the device body 302. The inner semi-closed flexible ring 308may be made of natural or synthetic elastomeric or polymeric material,and may be attached by adhesive, welding, or other suitable attachmentmethod. The inner semi-closed flexible ring 308 may also be molded aspart of the device body 302. The inner semi-closed flexible ring 308includes an opening sufficient to permit insertion of the cannula. Theopening is also sufficiently snug around the surface of the cannula toseal, thus avoiding the entry of air into the device 300 during theinsertion of the cannula. This seal where the cannula contacts thesemi-closed flexible ring 308 separates the liquid inside the cannulaand the device 300 from the air outside the cannula and the DIP device300.

The external conduit 322 may be connected or linked to the air outlet330 formed in the device body 302. The external conduit 322 may be madeof natural or synthetic elastomeric or polymeric material. The externalconduit 322 may be filled with a female plug 320, which may be formed topermit the insertion of a syringe for extracting fluid and air bubblesfrom the DIP device 300. In one example, the female plug 320 may be afemale luer-type plug, and may be fixed to the external conduit 322 byadhesive or other fixing means. The female plug 320 may also bemanufactured, for example, by molding the female plug 320 and theexternal conduit 322 with the device body 302 as a single unit. Theexternal conduit 322 may also include a male plug 326, which may be usedto cover the female plug 320 or as a tap to control the inflow andoutflow of liquids through the connecting device 300. In one exampleimplementation, the male plug 326 may be a male luer-type plug that maylock in with the female luer-type plug 320 to allow for selectivesealing and opening of the outlet 310 in the device body 302.

The detachment section 324 of the device body 302 may be formed with twoseams that run parallel along the length of the device body 302. Theseams are formed to allow the user to tear the detachment section 324from the rest of the device body 302. The flap 324 a extends from thedetachment section 324 to provide a grip to ease the act of pulling thedetachment section 324 from the device body 302. The detachment section324 may be made of a metallic or polymeric material, or any othermaterial that may provide a seal with the remainder of the device body302, yet permit easy removal of the detachment section 324 from thedevice body 302.

FIG. 5A shows a front view from the distal ending 304 of the DIP device300 of FIG. 3. The view in FIG. 5A shows the semi-closed flexible ring308, the external conduit 322, the female plug 320, the male plug 326,and the detachment section 324. The detachment section 324 is shown inFIG. 3A as that section of the device body 302 between two notches orcuts where the device body 302 is thinner than the rest of the devicebody 302.

FIG. 5B shows a cross-sectional view of the DIP device 300 at line A-Ashown in FIG. 5A. FIG. 5B shows flap 324 a extending from the detachmentsection 324 that allows the user to grasp the flap 324 a and pull thedetachment section 324 from the device body 302, thus allowing removalof the DIP device 300 from a cannulae/VAD assembly. Other means fortearing or separating the device body 302 may be used to allow removalof the DIP device 300 once the cannulae have been connected to a cardiaccirculatory support device.

The DIP device 300 may be used to connect a cardiac circulatory supportdevice to a patient. The cardiac circulatory support device may be aVAD, a blood pump, or any other type of pump or device used for pumpingblood or other liquid during a procedure requiring circulatory support.The examples described below refer to the use of DIP devices in thecontext of connecting cannulae to a VAD. However, it is to be understoodthat reference to a VAD is purely for purposes of providing adescription and is not intended as any kind of limitation. Examples ofVADs that may be used in the examples described below are described inU.S. Pat. No. 7,217,236 to Calderon et al., issued May 15, 2007, whichis incorporated herein by reference in its entirety.

FIGS. 6A and 6B illustrate an example of utilizing a DIP device toconnect cannulae to a cardiac circulatory support device. FIG. 6A showsa VAD 602 connected to a pair of DIP devices 608, 610. The VAD 602includes an inflow connector 604 and an outflow connector 606. The firstDIP device 608 is connected to the inflow connector 604 and the secondDIP device 610 is connected to the outflow connector 606.

Referring to FIG. 6A, a VAD/DIP device assembly 600 is formed byconnecting the first DIP device 608 to the input connector 604 of theVAD 602, and the second DIP device 610 to the output connector 606 ofthe VAD 602. The assembly 600 may then be filled with a liquid, such asa saline solution, and any air bubbles removed via the distal openingsof the DIP devices 608, 610. As described in further detail withreference to FIGS. 10-15B below, the liquid is added at the distalending of the DIP devices 608, 610 while the assembly 600 is orientedwith the distal endings pointing up. The VAD 602 is thus positioned soas to collect the liquid being poured into the assembly. Once theassembly 600 shown in FIG. 6A is filled with the liquid, any air bubblesmay be removed via the opening at the distal endings of the DIP devices608, 610.

FIG. 6B shows the VAD 602 connected to the two DIP devices 606, 608, andto cannulae 610, 612, which are inserted into corresponding DIP devices606, 608. The DIP devices 606, 608 are occluded using a pair of clamps620, 622, respectively. The two cannulae 610, 612 may then be surgicallyimplanted into the patient. While filling the cannulae 610, 612 and theDIP devices 606, 608 with liquid, the cannulae 610, 612 are insertedinto the DIP devices 606, 608, respectively. The two cannulae 610, 612may first be inserted partially into the DIP devices 606, 608,respectively. The ends of the cannulae 610, 612 may be held in the bodyof the DIP devices 606, 608 by the inner semi-closed flexible ring 108,FIG. 1. The cannulae 610, 612, the DIP device 606, 608 and the VAD 600may thus form a closed container of liquid. Any trapped air bubbles maybe removed via the external radially-disposed conduits 614, 616 on theDIP devices 606, 608, respectively.

FIG. 7 is a perspective view of an example assembly (“VAD/DIPdevice/cannulae assembly”) 700 that includes two DIP devices 708, 710,two cannulae 712, 714 and a VAD 702. FIG. 8 shows an explodedperspective view of the assembly in FIG. 7 illustrating how thecomponents fit with one another. FIG. 9 shows a longitudinalcross-sectional view of the assembly shown in FIG. 7, which alsoillustrates how the components fit with one another. Referring to FIGS.7, 8, and 9, the two DIP devices 708, 710 are connected to the VAD 702via respective connectors that include the input connector 704, whichconnects to the proximal ending 716 of the first DIP device 708, and theoutput connector 706, which connects to the proximal ending 718 of thesecond DIP device 710. The two cannulae 712, 714 are shown inserted intothe DIP devices 708, 710 at the distal endings 720, 722, respectively.

FIGS. 10-29B illustrate how examples of a DIP device in accordance withthe invention may be used to connect cannulae that have been surgicallyattached to a patient to a cardiac circulatory support device. Theillustrated examples depict attachment to a VAD; however, similarprocedures may be used for other cardiac circulatory support devices.

FIG. 10 is a perspective view of an example VAD 1000 that may be used ina VAD/DIP device/cannulae assembly such as that shown in FIG. 7. FIGS.11A and 11B illustrate attachment of two DIP devices 1100 a, 1100 b tothe example VAD 1000 of FIG. 10. The DIP devices 1100 a, 1100 b may beattached by an air-tight seal, which may be formed by a tight fit of theelastic material of the DIP devices 1100 a, 1100 b around the inflow andoutflow ports of the VAD 1000, respectively. An air-tight seal may alsobe formed using a clamp or other conventional sealing methods. The VAD1000 and attached DIP devices 1100 a, 1100 b, once assembled, form aVAD/DIP device assembly 1102 as shown in FIG. 11B.

FIGS. 12A and 12B illustrate adding a liquid 1202 to the VAD/DIP deviceassembly 1102 of FIG. 11B. The liquid 1202 may be added to the distalopenings 1204 and 1206 of either of the respective DIP devices 1100 a,1100 b as shown in FIG. 12A. As the liquid 1202 is poured into theVAD/DIP device assembly 1102, the liquid 1202 replaces the air insidethe VAD/DIP device assembly 1102. However, air bubbles 1210 may remainor form inside the VAD/DIP device assembly 1102. The liquid 1202 isadded to the VAD/DIP device assembly 1102 until the liquid level 1210 ineach DIP device 1100 a, 1100 b is above the air outlet at the externalconduit 1212, 1214, which may be closed by the engagement of a male lockplug in a closed position. While the liquid 1202 is being added, theVAD/DIP device assembly 1102 must be kept in the upright, verticalposition, with the distal endings up. With the level 1220 of the liquid1202 inside the VAD/DIP device assembly 1102 as shown in FIG. 12B, theDIP devices 1100 a, 1100 b may then be occluded below the air outlet atthe external conduits 1212, 1214, respectively, to close the containerof liquid.

Turning to FIG. 11, this figure illustrates occluding the DIP devices1100 a, 1100 b using a pair of clamps 1102 and 1104, respectively. FIG.14 illustrates turning the closed VAD/DIP device assembly 1102 liquidcontainer upside-down, causing any trapped air bubbles 1402 to collectin the VAD 1000. If necessary, the VAD/device assembly 1102 may beshaken or tapped to cluster or join the existing air bubbles 1402 in asingle air bubble.

The air bubbles once collected may then be moved back to one or both ofthe DIP devices 1100 a, 1100 b by turning the VAD/DIP device assembly1102 back over so that the DIP devices 1100 a, 1100 b again pointupwards, as shown in FIG. 14. When the VAD/DIP device assembly 1102 wasturned upside down in FIG. 14, the liquid contained in the space betweenthe clamps 1102 and 1104 and the proximal openings of the DIP devices1100 a, 1100 b empties out of the DIP devices 1100 a, 1100 b. FIG. 15Aillustrates removal of the clamp 1102 (not shown) from the first DIPdevice 1100 a to permit the addition of more liquid 1502 to the VAD/DIPdevice assembly 1102. The liquid 1502 may be added to the first DIPdevice 1100 a until the liquid level 1504 rises above the air outlet atthe external conduit 1212. As the liquid 1502 is added, the air bubbles1506 may be released at the open distal ending of the first DIP device1100 a. Once the liquid level 1504 has risen to a suitable level and airbubbles 1506 are released, the first DIP device 1100 a may be occludedagain with the clamp 1102 as shown in FIG. 11.

FIG. 15B illustrates the second DIP device 1100 b without the clamp1104, FIG. 11, that was sealing the liquid in the VAD/DIP deviceassembly 1102 from the space in the second DIP device 1100 b. FIG. 15Billustrates adding more liquid 1510 to the second DIP device 1100 b inthe VAD/DIP device assembly 1102. The liquid is added as shown in FIG.15B until the liquid level in the second DIP device 1100 b rises to asuitable level above the external conduit 1214 of the second DIP device1100 b, and any trapped air bubbles are released at the distal endingopening of the second DIP device 1100 b in the same manner as shown inFIG. 15A.

This purging process of the second DIP device 1100 b as well as thepurging process of the first DIP device 1100 a may be repeated as manytimes as necessary to achieve a liquid-filled, air bubble-free, VAD/DIPdevice assembly 1102. Turning to FIG. 16, this figure shows the VAD/DIPdevice assembly 1102 occluded with clamps 1102 and 1104, and ready forfurther manipulation, including the connection of cannulae to the VAD1000. The VAD/DIP device assembly 1102 as shown in FIG. 16 is filledwith a liquid and is also purged of any trapped air bubbles within theclosed liquid container portion of the VAD/DIP device assembly 1102between the two clamps 1102 and 1104.

In general, FIGS. 17A through 27 illustrate the connection of cannulaeto the VAD/DIP device assembly 1102 of FIG. 17A and the purging of airbubbles from the resulting VAD/DIP device/cannulae assembly. FIGS. 17A,17B, and 17C illustrate the connection of a first cannula 1700 to theVAD/DIP device assembly 1102 shown in FIG. 16. In FIG. 17A, theair-purged, bubble-free VAD/DIP device assembly 1102 is placed facingthe distal ending of the first cannula 1700 so that the first cannula1700 is in position for insertion into the first DIP device 1100 a atits distal ending. The first cannula 1700 is an output cannula withreference to the patient's heart as this is always the cannula that isfirst connected to the VAD (and an input cannula with reference to theVAD). During the cannulae-VAD/connector assembly connection process, theVAD/DIP device assembly 1102 may be manipulated or handled in anyposition, including the vertical, while retaining its air-purged andbubble-free condition. Although the first cannula 1700 may be surgicallyattached to a patient (not shown) at an end of the cannula 1700,unrestricted, controllable movements in the cannulae-VAD/connectorassembly connection process are still possible regardless of whichconnection method or cardiac circulatory support device may be used.

FIG. 17B illustrates adding a liquid 1702 to the first cannula 1700 andto the first DIP device 1100 a while the first DIP device 1100 a remainsoccluded by clamp 1102. In FIG. 17C, the liquid 1702 is added to boththe first cannula 1700 and the first DIP device 1100 a as the open endof the first cannula 1700 and the distal ending of the DIP device 1100 aare placed in close proximity to one another. The liquid 1702 is pouredinto both as the cannula 1700 is inserted into the first DIP device 1100a. This minimizes the possibility of having air bubbles enter into thespace inside the first DIP device 1100 a.

FIG. 18 illustrates the first cannula 1700 partially inserted into thefirst DIP device 1100 a. The cannula 1700 is inserted until the endadvances past the inner semi-closed flexible ring 1800. In FIG. 19, theclamp 1102 occluding the first DIP device 1100 a is removed, creating aclosed container of liquid in the first cannula 1700, the first DIPdevice 1100 a, the VAD 1000, and the second DIP device 1100 b up to thepoint at which the clamp 1104 creates the remaining occlusion. FIG. 20illustrates further insertion of the first cannula 1700 into the firstDIP device 1100 a until a connection is established at connector 2000with the inflow port of the VAD 1000.

Once the outflow cannula is connected to the VAD/DIP device assembly andpurged, the process must be repeated for the inflow cannula (withreference to the patient's heart). Turning to FIG. 21, a second cannula1720 is shown prior to insertion into the second DIP device 1100 b thatis still occluded by the clamp 1104. FIG. 22 illustrates liquid 2202being poured into the distal endings of the second cannula 1720 and thesecond DIP device 1100 b. In FIG. 21, the liquid 2102 is beingsimultaneously poured into both the second cannula 1720 and the secondDIP device 1100 b as the second cannula 1720 is inserted into the secondDIP device 1100 b, thereby preventing the introduction of air into theVAD/DIP device assembly 1102. In FIG. 24, the second cannula 1720 isinserted into the VAD/DIP device assembly 1102 such that the tip of thesecond cannula 1720 moves beyond the inner semi-closed flexible ring2402. Clamp 1104 remains in place, partially occluding VAD/DIP deviceassembly 1102.

As the second cannula 1720 is inserted in the second DIP device 1100 b,air bubbles 2502 may form in the space inside the second DIP device 1720as shown in FIG. 25A. These air bubbles may be removed utilizing asyringe that is inserted into the external conduit 2504 of the secondDIP device 1100 b after removing the male plug 126 from female plug 120(FIGS. 1, 2, and 3). In FIG. 25B, the syringe 2510, filled with a liquidand with plunger 2512 extended, is shown inserted into the externalconduit 2504 of the second DIP device 1100 b. In FIG. 25C, the plunger2512 of the syringe 2510 is shown depressed downward, which injects theliquid into the second DIP device 1100 b, thus creating additionalpressure in the second DIP device 1100 b.

Turning to FIG. 25D, the plunger 2510 is shown with the plunger 2512extended upward. This causes the air bubbles 2508 to be extracted fromthe second DIP device 1100 b into the syringe 2510. Once this is done,the syringe 2510 is removed from the external conduit 2504 of the secondDIP device 1100 b, the male plug 126 is fitted back over the female plug120 (FIGS. 1, 2, and 3), and the clamp 1104 is removed, as shown in FIG.26. FIG. 27 shows the cannula 1720 inserted further into the second DIPdevice 1100 b until a connection is established at connector 2004 withthe outflow port of the VAD 1000. The result is an air-purged,bubble-free VAD/DIP device/cannulae assembly 2700.

In general, FIGS. 28A and 28B illustrate removal of the first DIP device1100 a from the VAD/DIP device/cannulae assembly 2700 and FIGS. 29A and29B illustrate removal of the second DIP device 1100 b. The first DIPdevice 1100 a is detached from the VAD/DIP device/cannulae assembly 2700by pulling on the flap 2802 a, leaving the assembly 2700 shown in FIG.28B. This process is repeated for the second cannula 1720 as shown inFIG. 29A, with the end result being the cannulae/VAD assembly 2900 shownin FIG. 29B, where cannulae 1700 and 1720 are shown connected to VAD1000 through connectors 2902 and 2904, respectively.

FIG. 30 shows an example connector 3000 that may be used to connectcannulae to a VAD, such as connectors 2902 and 2904 as shown in FIG. 29.Connector 3000 has a distal ending 3002 and a proximal ending 3004 andmay be attached to the inflow and outflow ports (not shown) of a VAD,with the distal ending 3002 attached to the ports. The DIP devices arethen attached at the proximal ending 3004 and later the distal endingsof the cannulae are also attached. The connector 3000 may be adapted tothe cannulae to be attached so as to reduce turbulence in the fluid flowthroughout the cardiac circulatory support system and to avoid flowdrain from the system or air inflow into the system. The connector 3000may be made of stainless steel or other suitable material. FIG. 31 showsthree (3) examples of cannulae that may be utilized in accordance withthe invention, such as cannulae 1700 and 1720 shown in FIG. 29B.

FIG. 32 shows a flowchart illustrating an example method of operationthat uses DIP devices in accordance with the invention to connectcannulae to a cardiac circulatory support device and then, using the DIPdevice, to purge any air bubbles that may have entered thecannulae/cardiac circulatory support device assembly. The method ofoperation starts in step 3302 where a DIP device is connected to theinflow and outflow ports of a cardiac circulatory support device, whichin this example method is a ventricular assist device (“VAD”). Thisconnection is made utilizing connectors that are attached to the portsof the VAD and one DIP device is attached to the proximal ending of eachconnector.

In step 3304, the VAD/DIP assembly is turned VAD-side down, and a liquidis poured into both DIP devices. Each of the DIP devices may then beoccluded with a clamp. Next, in step 3306, air bubbles are purged fromthe VAD/DIP assembly by inverting the VAD/DIP assembly, removing one ofthe clamps from a DIP device, and pouring more liquid into the DIPdevice to force the trapped air out the distal ending of the DIP device.This sequence of steps is illustrated in FIGS. 15A and 15B.

In step 3308, the occluded VAD/DIP assembly is maneuvered so as toposition the distal endings of the cannulae facing the distal endings ofthe assembly, as shown in FIG. 17A. In next step 3310, the cannulae areinserted into the VAD/DIP assembly while pouring liquid into the distalendings of the cannulae and the DIP device, and also pouring the liquidover the gap between the cannulae and the DIP devices when inserting thecannulae into the DIP devices.

In step 3312, the air bubbles are purged from each of the DIP devices.More details of this process are shown in FIGS. 25A, 25B, 25C, and 25D.In step 3314, the clamps are removed from the DIP devices and thecannulae are moved further into the DIP devices until a connection ismade between the cannulae and the connectors attached to the VAD.

In step 3316, the DIP devices are removed from the VAD/DIPdevice/cannulae assembly, as shown in FIGS. 28A, 28B, 29A, and 29B. Theprocess ends in step 3318, with the cannulae/VAD assembly that is shownin FIG. 29B.

While various implementations of the invention have been described, itwill be apparent to those of ordinary skill in the art that many moreembodiments and implementations are possible that are within the scopeof this invention. Moreover, it will be understood that the foregoingdescription of an implementation has been presented for purposes ofillustration and description. It is not exhaustive and does not limitthe claimed inventions to the precise form disclosed. Modifications andvariations are possible in light of the above description or may beacquired from practicing the invention. The claims and their equivalentsdefine the scope of the invention.

1. A disposable purging (“DIP”) device for connecting cannulae to acardiac circulatory support device for use in a cardiac circulatorysupport system, the DIP device comprising: a device body having a distalending and a proximal ending; an inner semi-closed flexible ringpositioned in the inner surface of the device body; an air outlet formedin the device body between the distal ending and the proximal ending;and a radially-disposed external conduit positioned in the air outlet.2. The DIP device of claim 1, further including: a female plugconfigured to fit into the external conduit; and a male plug configuredto cover or plug the female-type plug.
 3. The DIP device of claim 2,where the female plug is a luer type plug and the male plug is a luerlock plug.
 4. The DIP device of claim 3, wherein the device bodyincludes a detachment section configured to be separable from the devicebody.
 5. The DIP device of claim 4, wherein the detachment sectionincludes a flap extending from the detachment section and positioned tobe grasped and pulled from the device body.
 6. The DIP device of claim2, further including means for separating the device body away from aconnection of cannulae and the cardiac circulatory device in anassembled state.
 7. The DIP device of claim 2, wherein the DIP device ismade of a natural or synthetic elastomeric or polymeric material.
 8. Amethod for connecting cannulae to a cardiac circulatory support device,the method comprising: connecting an inflow disposable purging (“DIP”)device and an outflow DIP device to an inflow port and an output port,respectively, of a cardiac circulatory support device to form a supportdevice/DIP device assembly; purging the support device/DIP deviceassembly of trapped air; occluding the inflow DIP device and the outflowDIP device; inserting an outflow cannula into the inflow DIP device andan inflow cannula into the outflow DIP device; purging air bubbles fromeach of the inflow DIP device and the outflow DIP device; and connectingthe cannulae to the cardiac circulatory support device to form a supportdevice/DIP device/cannulae assembly.
 9. The method of claim 8, furtherincluding the step of removing the inflow DIP device and the outflow DIPdevice from the support device/DIP device/cannulae assembly.
 10. Themethod of claim 8, wherein the step of connecting the inflow DIP deviceand the outflow DIP device to the cardiac circulatory support deviceincludes attaching a connector to the inflow port and to the outflowport of the cardiac circulatory support device.
 11. The method of claim8, wherein the step of purging the support device/DIP device assembly oftrapped air includes: filling the support device/DIP device assemblywith a liquid; occluding one of the DIP devices; pouring additionalliquid into the other DIP device to force the trapped air out of adistal ending of the other DIP device; and occluding the other DIPdevice.
 12. The method of claim 11, where the liquid is a salinesolution.
 13. The method of claim 8, where the step of inserting anoutflow cannula into the inflow DIP device and an inflow cannula intothe outflow DIP device includes: positioning the support device/DIPdevice assembly facing distal endings of the outflow and inflowcannulae; inserting the outflow cannula into the inflow DIP device whilepouring a liquid over the distal ending of the outflow cannulae and adistal ending of the inflow DIP device; removing the occlusion from theinflow DIP device; and further inserting the outflow cannula into theinflow DIP device until the outflow cannula connects to the inflow portof the cardiac circulatory support device.
 14. The method of claim 13,further including the step of repeating the steps of claim 13 for theinflow cannula and the outflow DIP device.
 15. The method of claim 14,where the step of purging air bubbles from each of the inflow DIP deviceand the outflow DIP device includes extracting the air bubbles from theDIP devices using a syringe inserted into an external conduit of the DIPdevices.
 16. The method of claim 14, where the liquid is a salinesolution.
 17. The method of claim 8, where the cardiac circulatorysupport device is a ventricular assist device (“VAD”).
 18. A system forconnecting cannulae to a cardiac circulatory support device for use in acardiac circulatory support system, the system comprising: twodisposable purging (“DIP”) devices each having a distal ending and aproximal ending; a cardiac circulatory support device for use in acardiac circulatory support system having inflow and outflow ports;connectors configured to attach the distal ending of a connector to eachof the inflow and outflow ports; and cannulae configured for attachmentto each of the inflow and outflow ports.
 19. The system of claim 18,where the cardiac circulatory support device is a ventricular assistdevice (“VAD”).
 20. The system of claim 19, where the DIP devicesinclude an air outlet adaptable for the removal of air from an assemblyincluding the VAD and the DIP devices.